Safety control for power operated machines



Haw-P1 5m ngmrgnc alUH "00m nmog XR P35319025 Oct. 5, 1943. w. F.GAYRING 2,331,023 '7 SAFETY CONTROL FOR POWER OPERATED MACHINES FiledApril 9, 1942 3 Sheets-Sheet l FIG.|

INVENT OR.

ALLACE EGAYRING ATTORNEYS MOSS HBIUWHCB Wm W nuum Oct. 5, 1943. w. F.GAYRING 2,331,023

SAFETY CONTROL FOR POWER OPERATED MACHINES Filed April 9, 1942 3Sheets-Sheet 2 FIG.4

1N VENTOR. WALLACE F.GAYR ING ATTORNEYS Oct. 5, 1943.

U038 fiererence ovum" mom W. F. GAYRlNG SAFETY CONTROL FOR POWEROPERATED MACHINES Filed April 9, 1942 3 Sheets$heet 3 INVENTOR WALLACEF. GAYRING ATTORNEYS Patented Oct. 5, 1943 SAFETY CONTROL FOR POWEROPERATED MACHINES Wallace F. Gayring, Minoa, N. Y., assignor to TheProsperity Company, Inc., Syracuse, N. Y., a corporation of New YorkApplication April 9, 1942, Serial No. 438,308

7 Claims. (Cl. 25041.5)

This invention relates to safety controls for power operated machineshaving an opening and closing movement, as garment and laundry pressingmachines, and has for its object a control ating circuits for thecontrol of the machine, when a timer is used to open the press.

This safety control includes a control element operable to control theflow of power to the for such machines operated by light from asourcemotor of the actuating mechanism of the mareflected from the operatorwhen within the operchine, as a pressing machine, means for operating ordanger zone of the machine, for openating the control including a sourceof light, a ing the machine or holding it open and to effectphotoelectric cell arranged out of the path of the the closing of themachine, when the operator rays from the source of light and in the pathof moves out of the operating zone, so that no light 10 the raysreflected from a person, as the operator, is reflected on thephotoelectric cell from a source coming within the range of theoperating zone, of light. The operator may wear a white apron electronicamplifying circuits controlled by the or any other object facilitatingthe reflection of photoelectric cell and controlling a feed circuit thelight. for an electro-responsive device or relay which The inventionfurther has for its object a maoperates the power control element. chineembodying such a control in which the The invention is shown as embodiedin a operating means also embodies a timer for openplaten laundry pressincluding a stationary lower ing the machine after a predetermined time,even pressing element or buck, and a power actuated though the operatoris away from the machine, press head movable toward and from the buck.or out of the operating zone thereof, the oper- As illustrated in Figure4, the motor of the ating of the timer cutting out the press closingactuating means is a cylinder and piston motor circuits, and additionalphotoelectric cell conand the power is compressed air. Hence, thetrolled circuits operating to again out in the norcontrol element is avalve. mal control circuits when the operator again The operator usuallyworks on a plurality of, comes into the operating zone of the machine,here shown as two, machines. When making a after it has been opened bythe timer, so that lay on one machine, the other machine is closed. whenthe operator now steps out of the zone, the When the operator moves awayfrom one machine press will close. out of the range of the source oflight thereon, The invention consists in the novel features the openmachine closes automatically, and when and the combinations andconstructions hereinthe operator comes within the range of the otherafter set forth and claimed. machine and the light reflects from theoperator In describing this invention, reference is had on to thephotoelectric cell, that machine opens. to the accompanying drawings inwhich like The machines here shown as paired to be tended charactersdesignate corresponding parts in all by one operator, are designated Aand B. Each the views, machine includes a suitable frame I, a lowerFigure 1 is a side elevation of a pressing mapressing element or buck 2mounted above a table chine embodying this invention, the same being top3 on the frame I, and an upper pressing eleshown as in open position,because the operator ment or head 4 having an operating movement iswithin the range of the source of light, so toward and from the buck 2.The head 4 is that light is reflected from the operator onto the shownas carried by a lever 5 pivoted at 6 to an photoelectric cell or cells.upright bracket 1 rising from the frame in the Figure 2 is a sideelevation of a similar marear of the buck. The lever 5 is actuated byany chine when the press is closed showing its locasuitable mechanismincluding a motor, and motion to the first machine. tion transmittingmeans between the motor and Figure 3 is a diagrammatic view of themachine the lever 5. The motor is here shown as pressure irame and theangles at which the light will be operated and includes a cylinder 8 anda single reflected from the operator onto the photoelectric actingpiston 9 therein, the motion of which is cell when the operator iswithin the operating transferred through the piston rod l0 and suitablemechanism including an element H. The 4 is a diagrammatic view of theoper- 5 press opens under the action of countersprings. uit and theamplifying circuit for con- As the motion transmitting mechanism formsno i it and a source of light, and photoelectric part of this inventionand as various forms of cell an lngement for energizing the electroniccirmotion transmitting mechanisms are well known, cult, the motor of themachine being also shown. further description is thought to beunnecessary Figure 5 is a diagrammatic view of the operfor anunderstanding of this invention.

oa s

l7. designates the element for controlling the flow of power to themotor, and as the power is a pressure fluid, as compressed air, thiscontrol element is a valve of the combined intake and exhaust type. Thevalve includes a casing I3" having a double valve member l4 therein,which carries a normally open intake valve head l5 and a normally closedexhaust valve head l6, these being connected together so that they actas a unit. The valve member I4 is pressed by a spring H in a directionto close the intake head and open the exhaust head IE, but, as will behereinafter explained, the valve member is normally held with theexhaust valve head open, as seen in Figure 4. The intake end of thecasing I3 is connected by a pipe [8 to a suitable source of compresesdair, and the valve casing is connected by a pipe ill to the intake endof the cylinder 8.

2n designates the source of light, as a lamp bulb, connected in asuitable feed circuit controlled by a switch 2|. The switch is closed inthe normal operation of the machine. 22 designotes a photoelectric cellto be energized by the light rays from the source of light 20, but notby the rays di ectly therefrom, but from rays reflected from theoperator, as seen in Figure 1, when the operator comes within the rangeof the operating zone of the machine. The rays may be reflected from awhite apron or the dress of the operator, or from a special reflectingobject carried by the operator. There are usually three photoelectriccells located to receive the reflected rays when the operator is infront of the machine or on either lateral side thereof. Thephotoelectric cells are connected in circuits for energizing theamplifying circuit which, when amplified, operates a relay switch in acircuit in which the coils of a relay or solenoid are connected, therelay operating the valve member M to open it and hold it open, exceptwhen the operator comes within the operating zone of the machine.

23 designates the electro-responsive device or relay for operating thevalve member l4 of the control valve I2. The coils of the relay areconnected to service wires 24 and 25 by wire 26 and a wire 21 connectedto the movable arm 28 of the relay switch, said arm 28 being normallyengaged with the contact 29 connected by a wire 30 to the other feedwire 25. Thus, normally the circuit through the relay 23 is closed andthe control valve is operated with its intake valve head l5 open and itsexhaust valve head l8 closed. so that air is free to pass through thecylinder and close the press and hold it closed. The relay switch arm7.8 is the armature of a relay operated by the amplification of thecurrent in the electronic circuit. The electronic circuit may be of anywell known arrangement. That here shown includes a transformer 3|, theprimary coil 32 of which is connected across the feed wires 24, 25 andthe secondary coil 33 of which is connected by a tap or line 34 to thecathode 35 of a thermionic tube 36 and also by a tap 3'! and wire 38 tothe control grid 39 of the tube, the wire 37 being also connected tolike terminals of the photoelectric cells. The anode 4d of the tube isconnected by a wire 4| to the other terminals of the photoelectriccells. The secondary coil 33 is also connected by a tap 42 to one end ofthe rimary coil 43 of a relay, the other end of which is connected tothe wire 4| leading from the anode 40. The relay switch arm 28 is thearmature for the core 44 of the Cross helerence relay 43 and said switcharm 28 is normally spaced from the armature 44. A suitable condenser 45and resistance 45 around the condenser is located in the wire 37.

In operation of the form shown in Figure 4, the relay switch arm 23being in engagement with the contact 29, the relay '23 is energized, andhence the valve l4 in position shown in Figure 4, in which the intakevalve head I5 is open and the exhaust valve head it closed, and hencethe press closed. Then the rays from the sources of light 20 do notstrike any of the photoelectric cells 22. When, however, the operatorcomes within the operating range of the machine, the light reflects fromher garments onto one or more of the photoelectric cells depending uponthe angle at which she approaches the machine, whereupon the currentthrough the coils of the relay 43 are amplified sulficiently to causethe core 44 to operate the relay switch arm 28 to break engagement withthe contact 29, thus opening the circuit to the relay 23, permitting thespring H to close the intake valve head l5 and open the exhaust valvehead l6. Thus, air can exhaust from the cylinder back through the pineI9 past the open exhaust valve head Hi to the outer air through ports41. It will be understood that the press is opened by counterspringswhich are loaded during the closing movement of the press. As long asthe operator is within the operating zone in front or at the sides ofthe machine (Figure 3), at least one of the photoelectric cells will beenergized by light rays reflected from the operator, and hence the presswill remain open. When the operator steps away from the machine, or isin the position shown in Figure 2, relatively to the machine B, thelight rays are no longer reflected on any one of the photoelectriccells. ence the amplifying circuit and the relay 43 are de-encrgizcd, sothat the relay switch arm 28 again engages the contact 29 and closes thecircuit through the windings of the relay 23.

In Figure 5 is shown diagrammatically electronlc control mechanismembodying a timer for opening the press after a predetermined periodwithout requiring the presence of the operator in so doing, the timerbreaking the energizing circuit to the relay 23 which operates thecontrol valve, by opening a cut-out switch in the energizing circuit forthe relay 23 in series with the switch arm 28, and also an arrangementfor resetting the cut-out switch when the operator again comes withinthe operating zone of the machine and the light reflects onto any one ofthe photoelectric cells.

In Figure 5, the electro-responsive device or relay 23, or the movablemember thereof, instead of thrusting directly against the stem of thevalve member l4, as in Figure 4, operates through an intermediatemember, as against one arm of a lever 48 pivoted at 49 between its ends,the lever coacting at its other end with the plunger 50 operated by adiaphragm 5| in a diaphragm chamber 52, the pressure side of which icon-- nected by a pipe 53 to a port 55 in the side of the cylinder 8.The port is located to be uncovered by the piston 9 when the pistonapproaches the end of its power stroke, and hence when the press isclosed. When the port is uncovered. air enters the diaphragm chamber,actuate the diaphragm therein and through the plunger 5 and the lever 48holds the control valve member I4 in the position it has been operatedby the relay 23, thus taking the control away from the neuron Hoomrelay. As the press is closed or nearly closed, when the piston 9-passes theport 55; the valve member M- is locked in its operatedposition by the closing of the press, regardless of whether the lockingoperation is-eifected by the movement of the piston 9-, or some otherpart of the motion transmitting means between the piston 9 and the presshead 4. As-it is old; in so far as this invention is concerned, to timethe locking of a. press closed by a port-in the side of the piston, orby motion transmitting means operated by the piston to close the press,or by other time locking means, the particular mechanism for timing thelocking of the control valve in operated position is, per se, not partof this-invention, and any suitable timed locking mechanism may be used.

The means for cutting out, or opening, the circuit to the relay 23 andfor timing the opening of the press and holding it open when theoperator is out of the operating zone and hence the light is not beingreflected onto the photoelectric cells, is designated by the numeral 56.This timer, as illustrated, includes a chamber 51' connected by pipes58, 59 to the port 55, it being shown as connected directly to the pipe53, a pressure regulating valve 60 in the pipe 58, a normally closed.spring pressed, exhaust valve 6| for open ng the pipe 59 to the outerair, and a diaphragm 52 exposed to the pressure in the chamber 51 andoperating a plunger 83, which plunger through suitable motiontransmitting means. as a lever 64, acts on the stem of the springpressed exhaust valve 6| to open it when a predetermined pressure isreached in the chamber 51. The pressure in the diaphragm chamber 52having been released, the control valve member I is operated to closethe intake valve head i5- and open the exhaust valve head It, so thatair may exhaust from the cylinder back through the pipe I9 and the valvecasing I3 to the outer air, so that the press is free to open under theaction of the countersprings. The valve 6| exhausts to the outer air, aswill be presently described.

The pressure regulating valve 60 may be of any suitable construction. Itis adjustable to vary the period it requires for the pressure to buildup to a predetermined degree in the chamber 51, and hence adjust thetime the press remains closed. The timer may also be of any suitableconstruction.

The means for operating a cut-out switch in the energizing circuit forthe relay 23 is also operated by the press locking means, and when thecut-out switch is operated, the press will not again close, after it hasbeen opened by the timer, even though the operator is out of theoperating zone and no light reflected onto the photoelectric cell.

Means is also provided for again closing the energizing circuit throughthe relay 23 or for resetting the cut-out switch when the o erator comesinto the operating zone. When the operator comes into the operating zoneand the light is reflected onto one or more of the photoelectric cells,the cut-out switch is reset, but becaus the operator is in the operatingzone, the relay 23 will not be energized as long as she is in theoperating zone.

In the construction shown in Figure 5, the control valve l2, piston 9,and exhaust valve 6| in the pipe 59 leading to the chamber 5'! of thetimer through the pressure regulating valve 60, are shown in theirpositions assumed when the press has been opened by the timer and thecutout-switch in the energizing circuit for the relay 23-, opened.

65 designates thecut-out switch in the energizing circuit wires 26, 21'for the relay 23 and in series with the switch arm 28 in said circuit.66 is a movable, as a rocking, switch arm pivotally mounted between itsends in the switch 65 and normally bridging contacts 6-1, 68 of theswitch 65. When the press closes and the piston 9 passes the port 55, sothat air commences to flow to" the chamber 57 of the timer 56, throughthe pressure regulating valve 60, air also flows from the pipe 59 intothe casing of the exhaust valve 6|, which is closed. When thepredetermined pressure isreached in the chamber 51 of the timer 56, thediaphragm- 62- is deflected andthe motion thereof transferred throughplunger 63 to the movable member of the exhaust valve 6|. opening saidvalve against its spring. The air then passes through the casing of theexhaust valve 61 and a pipe 13' to a pressure operated device as acylinder 69 having a piston 10 therein, which through its rod H operatesan arm 12 connected to the switch arm 66. The piston 70 when thusactuated uncovers exhaust ports 10A in the cylinder 69' to permit theair to release from the diaphragm chamber 52 through pipes 53, 55, valve6| and pipe 13. Thus, when the press is closed, the piston 10 isactuated, and hence the switch arm 66 shifted out of contact with thecontacts til, 68, so that the circuit to the relay 22 is open. The presswill therefore remain open, even though the operator is out of theoperating zone and-no light being reflected onto the photoelectriccells.

The means for resetting the cut-out switch 66 in closed position, or inposition to bridge the contacts 61, 68. so as to return the control tothe relay 23, when the operator again enters the operating zone of themachine and light is reflecting onto the photoelectric cells, includes arelay '4, similar to the relay 23, and controlled by a switch arm 15normally spaced from contacts ll, 18 and brought into contact therewithwhen the core 44 of the relay 43 in the electronic amplifying circuit isenergized sufficiently to attract its armature or switch arm 28 to causesaid switch arm 28 to separate from the contact 29; The contact 18 isconnected to a wire 79. which is connected to one end of the windings ofthe relay 14, the other end being connected by wire 18 to the feed wire25, while the switch arm ll is connected by wire to the other feed line24. The switch arms 28 and 16 are mounted to work as a unit, butinsulated from each other, and in diiiercnt energizing circuitsconnected to the feed lines 24. 25. The switch arms are so mounted thatwhen the switch arm 28 is engaged with its contact 29, the switch arm 16is out of engagement with its contact ll, Ill and vice-versa. Therefore,when the press is closed and being held closed by the timer. the cut-outswitch 65 is closed and also the switch arm 28 in contact with thecontact 29 and the switch arm 16 out of contact with the contact 29 andthe switch arm 15 out of contact with the contacts 71 and 18. Whensuificient pressure is built up in the chamber 57 of the timer 56 todeflect the diaphragm 62 and open the exhaust valve BI and the press,the air passes from the valve casing 6! through pipe 73 to the cylinder69 and actuates the piston therein to cause its rod H to shift theswitch arm 66 out of engagement with contact l1 and open the circuit tothe relay 23. When the operator returns to within the operating zone,and hence light is reflected on one or more of the photoelectric cells,the coils 43 of the relay in the electronic circuit are energizedsufliciently to cause the core 44 to shift the switch arm 28 out ofengagement with the contact 29 and shift the switch arm 16 intoengagement with the contacts ll, 18 so that now the circuit to thewindings of the resetting relay M are energized, causing the movablemember to push the piston in through its rod ll upwardly, rocking thearm 12 upwardly to reset the cut-out switch arm 16 in the position inwhich it engages the Contact 61. However, the circuit to the relay 23 isopen, because of the switch arm 28 being separated from the contact 29.When the operator moves out of the operating zone, the relay 43 of theelectronic circuit is de-energized, and hence the switch arm 28 of therelay engages the contact 29 and closes the energizing circuit to therelay 23 and opens the energizing circuit to the relay 14. Hence thepress closes on the next operation.

A manually operable release valve 90 is provided, this being shown asconnected in the pipe 59, so that the press may be opened at any time,regardless of the automatic control. This valve 90 may be a remotecontrol, that is, the valve 90 for machine A may be located near machineB, and the valve 80 for machine B may be located adjacent machine A. Thevalve 90 exhausts through pipe 9| which is connected to pipe 13 leadingto cylinder '10. Hence, when the manual valve 90 is opened, the airexhausts from the diaphragm chamber 52 through pipe 59, casing of valve90, pipes 9|, '3 and out through ports A prior to the resetting of theswitch arm 66 by the relay 74.

What I claim is:

1. A safety control for machines having an opening and closing movementand embodying power actuating mechanism including a motor; said controlincluding a power control element operable to control the flow of powerto the motor, means for controlling the operation of said elementincluding an electro-responsive means, an energizing circuit therefor,switch means in said circuit, sources of light, a photoelectric cellmeans arranged out of the path of the rays from the sources of light andin the path only of reflected rays of the sources of light from a personcoming within the operating zone of the machine, and amplifying circuitscontrolled by the photoelectric cell having a relay therein foroperating said switch means, the sources of light and the photoelectriccell means being located to receive reflected rays from at least thefront and lateral sides of the machine.

2. A safety control for machines having an opening and closing movementand embodying power actuating mechanism including a motor; said controlincluding a power control element operable to control the flow of powerto the motor, means for controlling the operation of said elementincluding an electro-responsive device, an energizing circuit therefor,a switch in said circuit, a source of light, a photoelectric cellarranged out of the path of the rays from the source and in the path ofreflected rays of the source from a person coming within the operatingzone of the machine, amplifying circuits controlled by the photoelectriccell and having a relay therein for operating said switch, andreleasable means for locking the machine closed independently of thephotoelectric cell control.

3. A safety control for machines having an opening and closing movementand embodying a power actuating mechanism including a motor, saidcontrol including a power control element operable to control the flowof power to the motor, means for controlling the operation of saidelement including an electro-responsive device, an energizing circuittherefor, a normally closed switch in said circuit, a source of light, aphotoelectric cell arranged out of the path of the rays from the sourceand in the path of the reflected rays of the source of a person comingwithin the operating zone of the machine, an electronic amplifyingcircuit controlled by the photoelectric cell and having a relay thereinfor operating said switch to open it, releasable means for holding thecontrol element operated independently of the photoelectric cell controland the eiectro-responsive device, a normally closed cut-out switch inthe energizing circuit in series with the former switch and operableinto open position by the locking operation of the releasable lockingmeans, and means for resetting the cut-out switch in closed positionupon the release of the locking means including a secondelectro-responsive device and an energizing circuit therefor having anormally open switch therein controlled by the photoelectric cell andamplifying circuit and movable into closed position thereby when theswitch in the first energizing circuit is moved to open position.

4. A safety control for machines having an opening and closing movementand embodying a power actuating mechanism including a motor, saidcontrol including a power control element operable to control the flowof power to the motor, means for controlling the operation of saidelement including an electro-responsive device, an energizing circuittherefor, a normally closed switch in said circuit, a source of light, aphotoelectric cell arranged out of the path of the rays from the sourceand in the path of the reflected rays of the source of a person comingwithin the operating zone of the machine, an electronic amplifyingcircuit controlled by the photoelectric cell and having a relay thereinfor operating said switch to open it, releasable means for holding thecontrol element operated independently of the photoelectric cell controland the electroresponsive device, a normally closed cut-out switch inthe energizing circuit in series with the former switch and operableinto open position by the locking operation of the releasable lookingmeans, and means for resetting the cut-out switch in closed positionupon the release of the locking means including a secondelectro-responsive device and an energizing circuit therefor having anormally open switch therein controlled by the photoelectric cell andamplifying circuit and movable into closed position thereby when theswitch in the first energizing circuit is moved to open position, saidlocking means including a timer controlled by the operation of theactuating means and operable to release the actuating means after apredetermined time period.

5. A safety control for machines having an opening and closing movementand embodying power actuating mechanism including a motor; said controlincluding a power control element operable to control the flow of powerto the motor, means for controlling the operation of said elementincluding an electro-responsive device, an energizing circuit therefor,a switch in said circuit, a source of light, a photoelectric cellarranged out of the path of the rays from the source and in the path ofreflected rays of the source from a person coming within the operatingzone of the machine, amplifying circuits controlled by the photoelectriccell and having a relay therein for operating said switch, releasablemeans for locking the press closed independently of the photoelectriccell control, timer means operable automatically by the actuation of themotor when closing the press, to release the locking means, a normallyclosed second switch in the energizing circuit for the normally closed,electro-responsive device in series with the first switch, and meansoperated by the actuation of the motor to open said switch when thepress closes and thereby cut out the electroresponsive device.

6. A safety control for machines having an opening and closing movementand embodying power actuating mechanism including a motor, said controlincluding a power control element operable to control the flow of powerto the motor, means for controlling the operation of said elementincluding an electro-responsive device, an energizing circuit therefor,a switch in said circuit, a source of light, a photoelectric cellarranged out of the path of the rays from the source and in the path ofreflected rays of the source from a person coming within the operatingzone of the machine, an electronic amplifying circuit controlled by thephotoelectric cell and having a relay therein for operating said switch,releasable means for locking the press closed independently of thephotoelectric cell control, a normally closed second switch in theenergizing circuit for the electro-responsive device, means controlledby the actuation of the motor, to open said switch, and thereby cut outthe electro-responsive device, an additional electro-responsive deviceand a normally open energizing circuit therefor controlled by thephotoelectric cell controlled amplifying circuit for resetting thesecond switch in position to close the energizing circuit of the firstelectro-responsive device.

7. A safety control for machines having an opening and closing movementand embodying power actuating mechanism including a motor, said controlincluding a power control element operable to control the flow of powerto and from motor means for controlling the operation of said elementincluding an electro-responsive device, an energizing circuit therefor,a normally closed switch in said circuit, a source of light, aphotoelectric cell arranged out of the path of the rays from the sourceand in the path of reflected rays of the source from a person comingwithin the operating zone of the machine, an electronic amplifyingcircuit controlled by the photoelectric cell and having a relay therein,said normally closed switch constituting the armature of the relay andbeing opened when the relay is energized, releasable means operable tolock the press closed independently of the photoelectric cell control,timer means controlled automatically by the closing of the machine bythe motor to release the locking means, a normally closed cutout switchin the energizing circuit for the electro-responsive device in serieswith the former switch, means operated by the operation of the motor toopen the cut-out switch, an additional electro-responsive device forresetting the cutout switch in closed position, and an energizingcircuit therefor controlled by the photoelectric cell controlledamplifying circuit, and a normally open switch therein, operated toclosed position, by the relay operating the first switch, to openposition.

WALLACE F. GAYRING.

